Note: Effects of several thermal glues used on temperature dependent Hall measurements

Abstract

The effects of four thermal glues (cry-con, fixogum, RS 503-357, and silicon-high vacuum-grease from Leybold vacuum) on temperature dependent Hall measurements on n-type silicon are tested. All thermal glues yielded the same results (resistivity, mobility, and charge carrier density) between 300 and 190 K. The use of RS 503-357 drastically distorts the expected results below 190 K, probably due to a phase transition and its latent heat, which affects the sample temperature during the phase transition. All the other thermal glues give reproducible results down to 100 K. Below 100 K, the use of cry-con, fixogum, and the silicon-high vacuum-grease from Leybold vacuum yield decreasing mobility and charge carrier density and increasing resistivity, as temperature decreases, but with different magnitudes. This is explained as the thermal properties of each glue start to diverge. Fixogum seems to give the best thermal conductivity, while the silicon-high vacuum grease from Leybold vacuum performs the worst below 100K. Crycon has an intermediate behavior between these two former ones. Cooling speed plays an important role at these low temperatures.